1. Field of the Invention
The present invention relates to a hydraulic shovel, particularly to an improvement with regard to pedals for running or rotating a vehicle and to a lever for running or rotating the vehicle.
2. Description of Related Art
Conventionally, within a cab (operator""s platform) of a vehicle for operating a hydraulic shovel there are provided a pair of projecting levers for running/rotating the vehicle on a floor portion of the cab in front of and apart from a seat. The operator who sits on the seat activates a left hydraulic motor of an underlying running system via a left running/rotation lever, while he activates a right hydraulic motor via a right running/rotation lever.
There are also provided a pair of running/rotation pedals integrally united below the running/rotation levers, i.e., at a position close to the floor. The operator can achieve the same function as obtained via the left running/rotation lever, by operating on a left running/rotation pedal, an the same function as obtained via the right running/rotation lever, by operating on a right running/rotation pedal.
According to certain types of hydraulic shovels, however, the running/rotation levers and the running/rotation pedals are separated from each other because otherwise the running/rotation levers would interfere with the sight of the operator. In some of them, a pair of running/rotation levers are gathered compactly on one side of the seat.
However, if the running/rotation levers are separated from the running/rotation pedals, and gathered compactly on one side of the seat, it is necessary for the operator to manipulate the two running/rotation levers with one hand which may complicate the operation.
To meet this problem, if the pair of running/rotation levers are installed one on each side of the seat, they will require for their manipulation both hands of the operator, which may pose a problem in certain situations.
A main object of this invention is to improve the operability of a hydraulic shovel.
This invention is characterized by comprising running/rotation pedals by which to run/rotate a vehicle, a single lever which is installed separately from the running/rotation pedals and which is similarly used for running/rotating the vehicle, and a control means which permits either the running/rotation pedals or the running/rotation lever to be available for operation at a given moment.
According to this invention configured as above, the operator can move a hydraulic shovel in a desired direction or rotate it on the same spot by operating on the running/rotation pedals with his feet, or can perform as well the same operation by manipulating the running/rotation lever with his hand. Because the running/rotation lever consists of a single lever, the operator can easily manipulate the lever with his single hand, being relieved of the complications and inconveniences encountered with the conventional hydraulic shovel. This improves the operability of the hydraulic shovel.
This invention is characterized by comprising a pair of left and right running/rotation pedals which output a running signal for forward or backward movement when the two pedals are concurrently depressed forward or backward, or a turn signal for leftward or rightward turn as the case may be when one of the two pedals is depressed forward or backward; a single running/rotation lever which outputs a running signal for forward or backward movement when the lever is slanted forward or backward, a steering signal for leftward or rightward turn as the case may be when the lever is rotated while it is kept slanted forward or backward, or a rotation signal for rotating the vehicle standing on a spot when the lever is rotated while it is kept at a neutral position; and a control means which permits either the pair of left and right running/rotation pedals or the single running/rotation lever to operate at a given moment.
According to this invention, as disclosed in the foregoing paragraph, it is possible to run or rotate the vehicle of a hydraulic shovel by operating by feet the pair of left and right running/rotation pedals, as well as by operating by hand the single running/rotation lever, which will serve to relieve the complications encountered with the conventional hydraulic shovel and to improve the operability of the machine.
According to this invention, the running/rotation lever is desirably installed close to one side of the operator""s seat.
According to the above configuration, the operator sitting on the seat can easily manipulate the running/rotation lever which will further contribute to the improvement of the operability.
According to this invention, there are desirably provided consoles on both sides of the seat one of which carries the running/rotation lever thereupon.
According to the above configuration, if the consoles are placed to have an appropriate height, they also serve as an armrest for the operator, which will allow the operator to operate the machine while taking a relaxed posture.
According to this invention, the operation controlling means desirably gives priority to the running/rotation lever in preference to the running/rotation pedals when running/rotating the vehicle is required.
According to this configuration, even when the running/rotation lever and the running/rotation pedals are manipulated concurrently, the operation via the running/rotation lever will be adopted in preference to the operation via the running/rotation pedals which will prevent the occurrence of wrong operations. In addition, while the operator operates on implement operation levers which of course must be attached to the left and right sides of the operator for allowing him to operate a hydraulic shovel, i.e., while the operator is working with an implement, he can run the vehicle by operating on the running/rotation pedals.
According to this invention, desirably, the running/rotation lever is provided with a signal output means which outputs a signal to the operation controlling means when the vehicle is run or rotated, and the operation controlling means controls such that the operator is allowed to run or rotate the vehicle by operating on the running/rotation pedals as long as there is no signal outputted by said signal output means.
According to this configuration, because the operation controlling means is provided with a signal from the running/rotation lever, and thus quickly and securely grasps the current operation state of the running/rotation lever, it can instantly determine whether the operation via the running/rotation pedals should be feasible or not.
According to this invention, the signal output means is desirably a grip detection sensor which monitors how the running/rotation lever is gripped and outputs a signal based on the monitoring result.
According to the above configuration, a signal is outputted as soon as the running/rotation lever is gripped, even if the running/rotation lever is not manipulated for a certain operation. Accordingly, even if the running/rotation pedals are manipulated, the request transmitted via the manipulation of the running/rotation pedals is rejected, as long as the running/rotation lever is held by the operator. Thus, for example, when the operator is engaged with a work which absolutely requires stoppage of the vehicle, the operator will be safely guarded against the risk of running the vehicle by wrongly operating on the running/rotation pedals by accident, as long as he uses the running/rotation lever for that work.
The running/rotation lever of this invention comprises a lever body which can be slanted, and a rotational knob attached to the lever body. When the lever body is slanted forward or backward, a running signal is outputted so as to cause the vehicle to run forward or backward; when the rotational knob is rotated while the lever body is being slanted forward or backward, a turn signal is outputted so as to cause the running vehicle to turn left or right; or when the rotational knob is rotated while the lever body is kept at a neutral position, a rotation signal is outputted so as to cause the vehicle to rotate on the spot.
According to the above configuration, because the operator can steer the vehicle or rotate the vehicle on the spot by simply operating on the rotational knob, it is possible to securely steer or rotate the vehicle by simply resorting to the single running/rotational lever.
According to the invention, the lever body of the running/rotation lever is desirably configured such that, if the lever body is slanted leftward or rightward, an adjustment signal is outputted so as to cause the distance between left and right tracks of the running system to be altered.
When operation effective for adjusting the inter-track distance is introduced, the distance between left and right tracks of the underlying running system is adjusted, and this operation requires only the running/rotation lever to be slanted in two opposite directions, i.e., leftward or rightward. In accordance with this, the single running/rotation lever will allow the operator to run or rotate the vehicle as well as to adjust the inter-track distance, if the system is configured, for example, such that slanting the lever body forward or backward will cause the vehicle to run forward or backward, while slanting the lever body in other directions will cause the inter-track distance to be altered.
According to this invention, guide grooves are desirably provided to constrain the slanting direction of the running/rotation lever.
According to the above configuration, because the slanting direction of the running/rotation lever is constrained by the guide groove, the risk of wrongly introducing the running/rotation operation instead of the adjustment of the inter-track distance or vice versa will be safely avoided.
According to this invention, the running/rotation lever is desirably provided with a control means that controls the operation involved in the adjustment of the inter-track distance.
According to the above configuration, simple slanting of the running/rotation lever will not lead to the adjustment of the inter-track distance as long as the control imposed by the control means is not released, and the risk of wrongly adjusting the inter-track distance by accident while the vehicle is running will be safely avoided.